Electric mat



W. G. JAMES.

ELECTRIC MAT.

(No Model.)

Patented Jan. Z4, 1893.

UNITED STATES PATENT OFFICE.

WILLIAM G. JAMES, OF HARLEM, ILLINOIS.

ELECTRIC MAT.

SPECIFICATION forming part of Letters Patent No. 490,353, dated January 24, 1893.

Application led September 29, 1892. Serial No. 447,271. (No model.)

To all whom t may concern:

Be it known that I, WILLIAM G. JAMES, a citizen of the United States, residing at I-Iarlem, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Mats, of which the following is a specification, reference being had therein to the accompanying drawings, in which- Figure l represents a perspective view of my electrical mat and Fig. 2 a transverse section of the same.

Thisinvention is designed to produce a very cheap and portable mat for use in connection with an electrical alarm, whereby when pressure is brought to bear upon the mat by the foot, or otherwise, the negative and positive plates of the same will be forced into electrical contact and cause the alarm to be sounded, as is more fully described hereinafter.

This mat is very simple in construction and consists essentially of buty two metal parts, namely, the lower or main plate a and the upper plate Z9, which are substantially rectangular in the present instance but which may be circular or otherwise shaped if desired. The plates may be constructed of any suitable metal but I have found that thin zinc plates work well in practice. The lower plate has its four edges bent upwardly and turned inwardly a short distance to form lian ges a', and the upper plate has its edges inserted within these flanges and is thereby securely retained in place on the upper plate. To prevent electected.

and made elastic so that it normally holds itself up out of contact with the lower plate, as shown in Fig. 2. The negative and positive wires are connected to the respective plates of the mat and to the bell and battery in the usual manner so that when the upper plate is stepped upon and is forced into contact `with the lower plate, the circuit will be closed and the alarm sounded. When the pressure is released from the mat the upper plate immediately springs up out of contact with the lower plate and the bell stops ringing, as is evident. n

It' it is desirable, or necessary, a few small springs or rubbers c', may be inclosed within the mat to assist in supporting the spring plate, but it is thought these springs will not be necessary in mats of ordinary size.

The advantages of this mat lie in its extreme simplicity, inexpensiveness and dura bility, and also in rits portability, this latter advantage permitting it to be readily placed wherever desirable.

Having thus fully described my invention what I claim is:-

An electrical mat consisting of alower plate provided with upturned flanges at its edges, an elastic upper plate having its edges insert ed in said fianges, this plate being normally held up out of contact with the lower plate and insulating material interposed between the edges of the two plates, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM G. JAMES.

Witnesses:

A. PETERS, AUG BEINGHEROG. 

